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UNITED STATES DEPARTMENT OF AGRICULTURE 




S^&*^3L 



ft BULLETIN No. 964 



Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 




Washington, D. C. 



PROFESSIONAL PAPER 



September 20, 1921 



GARDEN FLEA-HOPPER IN ALFALFA AND ITS 

CONTROL. 

By A. H. Beyer, Scientific Assistant, Cereal and Forage Insect Investigations. 



CONTENTS. 



Page. 

Introduction 1 

Origin and distribution 2 

Synonymy 3 

History of the species and its injuries 3 

Recent injuries 5 

Damage to alfalfa r> 

Host plants 8 

Description 11 

Adult 11 

Egg 14 

Nymph 14 

Life history and habits 17 

Mating 17 

O viposition 17 

Egg stage and process of hatching 19 



Page. 
Life history and habits — Continued. 

Number and length of instars 20 

Length of life of the adult 20 

Hibernat ion 20 

Spring appearance and number of genera- 
tions 21 

Feeding habits 21 

Protective habits 22 

Rearing methods 23 

Natural enemies 24 

Remedial and preventive methods 24 

Dusting and spraying tests in the field 24 

Summary 26 

Literature cited 27 



INTRODUCTION. 

Little information has been recorded regarding the biology, habits, 
and control of Halticus citri, known as the garden flea-hopper. Dr. 
F. H. Chittenden was the first to attach to Halticus citri (Ashmead), 
then known as Halticus uhleri (Giard), the common name, chosen 
because of the insect's injuries to truck crops and its saltatory power. 

In addition to other leguminous plants the insect attacks alfalfa, 
injuring the plant by sucking the juices, and in fields where heavy 
infestation occurs may cause the loss of 50 to 60 per cent of the crop. 
As little was known of the insect outside of its depredations on truck 
crops, observations and life-history studies on the garden flea- 
hopper on alfalfa were conducted during the years 1015, 1916, and 
part of 1917, at Columbia, S. C, and also a series of control experi- 
ments for the purpose of determining the most effective means of 
combating outbreaks of the pest. The bulletin, therefore, gives 
the results accomplished by means of a combination of field and labo- 
ratory experiments. 

48309°— 21-Bull. 964 1 






c~ 



BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 




ORIGIN AND DISTRIBUTION. 

The present known range of the garden flea-hopper covers a large 
portion of the United States (fig. 1) . This insect belongs to the family 
Capsidae of the Heteroptera, is quite generally distributed throughout 
the eastern half of the United States, and in most instances has 
been reported as injurious to crops. 

The garden flea-hopper is apparently American in origin. There 
are, however, two cases on record where it is reported as being de- 
structive to crops out- 
side of the United 
States, viz, Brazil and 
French Cochin China. 
In the latter region it 
seriously infested the 
peanut crop. 1 

During the summer 
of 1916 the writer 
made numerous ob- 
servations with a view 
of determining what 

Fig. 1.— Map showing States where the garden flea-hopper (Haltieus effect altitude might 
citri) has been found. have u?Qn the dig _ 

tribution of this species. Sweepings made at the points men- 
tioned below showed the presence of the adults and nymphs in 
the highest as well as the lowest altitudes where collections were 
made. The trip included visits during the month of August, 1916, 
to alfalfa and clover fields at Macon, Ga.; Gray, Ga.; Sylva, N. C. ; 
Waynesville, N. C. ; Asheville, N. C. ; Statesville, N. C. ; Columbia, S. C. ; 
and Gainesville, Fla. The territory covering these points included 
a range of altitude from 180 feet to 2,700 feet. Gray, Ga., which 
has an altitude of 500 feet, was the center of the 1915 outbreak. 

1 The following notes on the garden flea-hopper {Haltieus citri) and list of localities have been compiled 
from field studies in the United States and from specimens contained in the collections of the U. S. 
National Museum: Orange Springs, Fla., 1887 (W. H. Ashmead); Riley Co., Kans., Sept. 10, 1892 (C L. 
Marlatt); Washington, D. C.,June 22,1897; Columbia, Mo., no date (C V. Riley); Berkeley Springs, 
W. Va. (P. R. Uhler); Auburn, Ala., no date (P. R. Uhler); Experiment Station, Manhattan, Kans., 1889 
(E. A. Smith); Experiment Station, Hartford, Conn., Sept., 1914 (W. E. Britton); Stillwater, Okla., 
Oct., 1912 (C. E. Sanborn); Topeka, Kans., Aug. 30, 1917 (E. A. Popenoe); Chicago, 111., July 13, 1908 (J. J. 
Davis); Clemson College, S. C, July 16, 1909 (G. G. Ainslie); Nashville, Tenn., Sept. 5, 1910 (G. G. Ainslie); 
Experiment Station, Utah, 1893 (P. R. Uhler); Winchester, Va., July 13, 1913 (E. B. Blakeslee); Washing- 
ton, D. C, 1917 (F. H. Chittenden); Gray, Ga., 1915 (R. J. Stewart); Gray, Ga., May 26, 1915 (A. H. Beyer); 
Macon, Ga., May 27, 1915 (A. H. Beyer); Lafayette, Ind., Aug. 11, 1916 (J. J. Davis); Atlanta, Ga., Aug. 
25, 1916 (A. H. Beyer); Statesville, N. C, Aug. 31, 1916, Waynesville, N. C, Aug. 27, 1916 (A. H. Beyer); 
Asheville, N. C, Aug. 28, 1916 (A. H. Beyer); Charlotte, N. C, Aug. 31, 1916 (A. H. Beyer); Hagerstown, 
Md., Sept. 12, 1912 (H. L. Parker); Columbia, S. C, Oct. 5, 1915 (A. H. Beyer); Ithaca, N.Y., Oct., 1915 
(H. H. Knight); Boston, Mass., Sept., 1915 (H. H. Knight); Springfield, Mo., July, 1915 (H. H. Knight); 
Quincy, Fla., May 23, 1916 (F. H. McDonough); Lakeland, Fla., Dec. 16, 1916 (A. H. Beyer); Fulton Co., 
N. Y., Aug., 1911 (C. P. Alexander); Indianapolis, Ind., Aug. 25, 1916 (H; F. Dietz); Gainesville, Fla., 
Feb. 28, 1917 (A. H. Beyer); Charleston, Mo., May 26, 1916 (E. H. Gibson); Hot Springs, Ark., May, 1916 
(E. H. Gibson); Chapel Hill, N. C, Sept. 21, 1915 (P, Luginbill). 



uBRAtit & emmm 


'"••»f-* -■Mf. 




CFD 9.31921 





GARDEN FLEA-HOPPER IN ALFALFA. 3 

P. R. Uliler (J) 2 recorded the garden flea-hopper as having been 
found at the experiment station at Logan, Utah, which point has 
an approximate altitude of 4,700 feet above sea level. 

SYNONYMY. 

The garden flea-hopper was first named and described by Ash- 
mead (1) as Rhinocloa citri. E. A. Popenoe (2) in 1890 called it 
" H alliens minutus Uhler MS." During the same year Giard (3) re- 
named the species uhleri, since there was already a Halticus minutus 
Reuter. Distant (4, p. 430) in 1893 redescribed the species as Calo- 
coris canus, not recognizing its true affinities. 

Reuter (12) in 1909 first pointed out that Rhinocloa citri Ashmead 
and Halticus uhleri Giard were the same, but he left the species un- 
der the latter name until 1914, when H. G. Barber (15) used the 
combination " Halticus citri (Ashm.)" in print. 

The synonymy, therefore, is as follows: 

Halticus citri (Ashmead) Barber. 

Rhinocloa citri Ashmead (/). 

Halticus minutus (Uhler MS) Popenoe (2). 

Halticus uhleri Giard (5). 

Calocoris canus Distant (4). 

Halticus citri Barber (15). 

HISTORY OF THE SPECIES AND ITS INJURIES. 

Halticus citri seems first to have received economic mention in 1887, 
tfy W. H. Ashmead (1) , who found it on orange trees in Florida. 

In 1892 A. Giard (3) recorded it as being destructive to peanut and 
rice crops of French Cochin China and Singapore, Straits Settlements. 

This species, with Agalliastes bractatus Say, was reported from 
Kansas in 1890 (2) as follows: 

We have the past season observed two species of Capsidae, or plant-bugs, living in 
great numbers on the underside of the leaves of the garden bean, puncturing the 
tissues and sucking the sap, and by these punctures causing the death of the tissues 
in small, irregular patches, that appear upon the upper surface of the leaf as white 
spots. 

It was found by J. B. Smith (6, p. 133) in New Jersey during 1900 
injuring truck crops at the following places: New Brunswick, James- 
burg, Swedesboro, Madison, Camden County, and Vineland. 

In 1900 F. M. Webster (?) reported it from Wooster, Ohio. F. H. 
Chittenden (S) states: 

lu May and June, 1900, this insect was observed in some numbers on bean3 in dif- 
ferent localities, and some leaves were found to have been killed by its attacks. 
Beets and cabbage were also affected, but injury was less noticeable to these crops. 
In 1901 the writer noticed severe injury to ornamental morning-glory in the city of 
Washington. 

3 Reference is made by number (italic) to "Literature cited," p. 27. 



4 BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 

W. E. Britton (9) of Connecticut, during September, 1904, re- 
ceived specimens of the insect from Southport, Conn., with the state- 
ment that much injury was being done by it to smilax growing under 
glass. Injury to beans, beets, red clover, cowpeas, potatoes, chrys- 
anthemums, morning-glories, eggplant, cabbages, and pumpkins also 
occurred at that time. 

In 1907 F. H. Chittenden (10, p. 118) reported that the insect 
u lives in great numbers on the leaves, puncturing them so as to cause 
the death of the tissues in small irregular white patches. In its 
short-winged form it resembles the black flea-beetles, which affect 
potato, alike in appearance, in the nature of its work, and in its salta- 
tory power. Other food plants include potato, pumpkin, cabbage, 
ornamental plants, clover, and many weeds." 

In 1907 F. M. Webster recorded H. uhleri as destructive to al- 
falfa over small areas at Topeka, Kans. 

In the Yearbook of 1908 Dr. Chittenden (11) gives the following 
account of H. citri: 

The garden flea-hopper (Halticus uhleri Giard) was more or less injurious to cucum- 
bers, squash, and beans in New Jersey; to beans in the District of Columbia, and to 
lettuce and sweet potato in the trucking region of Norfolk, Va. 

C. E. Sanborn (14) found the species destructive to alfalfa in Okla- 
homa in 1912. During the same year J. J. Davis (13) gives the fol- 
lowing account of Halticus citri: 

This flea-hopper did much damage to smilax in several greenhouses around Chicago 
in 1908 . . . and just outside of the house the weeds were much infested with it — the 
latter fact probably accounting for its presence indoors. Early in the spring of 1909 
the adults — fully winged males and females as well as the short-winged form — were 
found abundant in one greenhouse at a date which would preclude any possibility of 
their having developed out-of-doors that spring; and they did not develop inside the 
greenhouses from eggs deposited the fall before, as the houses had been examined 
during the winter and not an active "hopper" found. It was also observed that the 
individuals became adult in the fall, as cold weather set in. From these observations 
it appears that the adults hibernate in greenhouses or out-of-doors and become active 
in the spring, when they deposit their eggs for that season's generation — instead of 
doing it in the fall before, as has heretofore been supposed. 

Following are from the notes of Mr. G. G. Ainslie, of the Bureau of 
Entomology : 

Clemson College, S. C, July 16, 1909: The alfalfa is conspicuously whitened by 
the adults and larvge of this bug which have come there from the adjoining peas. 
The habitats of the insect seem to be the same on alfalfa as peas. The adults are 
found on both sides of the leaves but mainly the lower, while the larvae are confined to 
the lower side. 

Nashville. Tenn., September 5, 1910: Found a field of alfalfa badly whitened by 
the attacks of this species. The plants looked sickly from the work of these bugs. 

July 13, 1913, Mr. E. B. Blakeslee of Winchester, Va., reported to 
Prof. A. L. Quaintance of the Bureau of Entomology the occurrence 
of enormous numbers of H. citri in alfalfa fields, both in the adult and 



GARDEN FLEA-HOPPER IN ALFALFA. 5 

nymphal stages. Mr. J. R. Stewart, of Gray, Ga., under the date of 
May 9, 1915, reported severe injury by the garden flea-hopper to a 
field of alfalfa that had yielded fine crops for two years. 

Mr. E. H. Gibson on May 26, 1916, reported it as being injurious to 
alfalfa at Charleston, Mo. 

RECENT INJURIES. 

During the year 1915 serious attacks by Halticus citri on cereal and 
forage crops in the South Atlantic States, and especially in Georgia, 




Fig. 2.— Alfalfa showing the effect of injury by the garden flea-hopper on the leaves. 

directed the attention of the Bureau of Entomology to the need of 
investigational work with respect to this insect. The late Prof. F. M. 
Webster, entomologist in charge of cereal and forage insect investi- 
gations, immediately instituted researches for the purpose of deter- 
mining suitable control measures. 

The writer began his investigations at Gray, Ga., May 26, 1915. 
In walking through the alfalfa fields at this place infestation by the 
garden flea-hopper was found exceedingly abundant, the insect being 
present in all stages of its life cycle; the distribution of the pest in 



6 



BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 



each field was found to be quite uniform excepting along the fences, 
where the plants were most seriously affected, leaves being discolored 
and dropping off, and the plants dying in frequent instances. 

It was observed that the injury caused to alfalfa by Halticus citri 
very closely resembled that of the red spider (Tetranychvs himacu- 
latus Harv.) . 

All the cereal and forage and truck crops, wild mulberry trees, 
peach trees, and a large number of weeds, including the briar and 




-At the right, norma] healthy leaves of red clover. At the center and left, leaves seriously af- 
fected by the garden flea-hopper. 

species of the mint family, were found infested with this insect. 
More noticeable damage, however, was shown by alfalfa, cowpeas, and 
clover than by other growing crops. 

DAMAGE TO ALFALFA. 

The injury which is inflicted on alfalfa and other plants is caused 
by both adults and nymphs. Damage is done by means of their 
sharp pointed mouth-parts which are inserted into the plant tissues. 
The short chitinized beak is thrust through the surface of the leaf or its 



GAP.BEX FLEA-HOPPER IN ALFALFA. 



petiole and sap is extracted, giving the leaves a bleached appearance 
and often killing them. In extreme cases the stems of the plants 
are attacked in like manner. The greatest amount of damage 
results from the loss of plant sap or juices. The leaves die and in 
many instances drop from the stems and cause the infested plants 
to appear as bunches of stubble. 'See figs. 2 to 

The loss to the crop has been estimated by the writer as high as 50 to 
60 per cent in several severely infested fields where the alfalfa had been 
cut and the cured hay removed. The damage is quite noticeable 




• .he garden flea-far.: 

in the field, since the plants have not the green color and freshness 
characteristic of plants that are uninjured.* and have become 
fibrous, contrasting with other plants of luxuriant growth and 
thrifty condition. The extraction of the plant juices checks the 
growth of the plant, causing it to shrivel up and in a number of 
instances to die. After the crop has been cut and the hay re- 
moved from the field an inspection of the alfalfa field shows that 
a large number of the leaves have fallen from the plants and 
been left lying on the ground, causing a loss of much of the food 



8 



BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 



value of the hay. This is due in large measure to the injury resulting 
from the feeding of the garden flea-hopper upon the petioles, leaves, 
and tender stems. 




Fig. 5. — Cowpeas showing the effect of injury by the garden flea-hopper on the leaves. 

HOST PLANTS. 

Throughout the South Atlantic States the species was found 
prevalent on alfalfa, the clovers, cowpeas, and some of the common 



GARDEN FLEA-HOPPER IN ALFALFA. 



9 



weeds. All common garden truck was also found to be among the 
favorite host plants with the possible exception of the red pepper 
plant which showed very slight attack or injury. It was found on 




Fig. 6.— Beggar-weed ( Meibomia tortuosa) showing the effect of feeding of the garden flea-hopper upon 

the leaves. 

plants in greenhouses the year round, and on the out-of-door flower- 
ing plants it was especially noticeable in the early spring and late 
fall, although also common throughout the summer. 

48309°— 21— Bull. 964 2 



10 



BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 



Tables I, II, and III were prepared after a close examination of 
the most seriously infested host plants collected from the fields in 
which outbreaks occured, and show that alfalfa is most frecmented 
by Halticus citri for egg laying. 

Table I. — Infestation in alfalfa by Halticus citri, showing the number of eggs in each 

leaf and where deposited. 



Eggs 
Leaf No. ^posited 
in upper 
I surface. 


Eggs 
deposited 
in lower 
surface. 


Total 

number 

of eggs 

deposited. 


Leaf No. 


Eggs 
deposited 
in upper 
surface. 


Eggs 
deposited 
in lower 
surface. 


Total 

number 

of eggs 

deposited. 


1 3 

2 .. . 


1 



7 

i 


4 

11 

19 
6 
3 
2 
7 
3 

15 
4 
5 
1 

29 
4 

15 

1 
7 

11 
2 

14 
4 
1 
7 
9 
1 


27 


3 3 

2 2 

3 3 
16 2 I 18 

30 , 30 
53 | 53 
10 7 1 17 

31 n 1 ai 


28 


3 


12 


29 


4 




30 




2 

1 1 
7 

3 

is ; o 

4 

5 1 
1 

28 


31 


. 


32 


7 


33 


8 


31 


9 . 


35 


6 
23 
15 
23 

2 




1 
15 
n 


6 
23 
16 
38 

1 


10... 


33 


11 


37 


12 


38 


13 


39 


14 


4 
5 

1 
2 

10 
2 

12 
2 
1 
6 
8 
1 



10 


5 
1 

4 
2 

1 
1 



40 


3 n 


15 


41 


5 
2 
2 
3 


5 

1 3 
2 
3 


16 


42 


17 


43 


18 


44 


19 


45 


5 5 
3 3 
7 18 
1 1 2 
20 1 21 
9 9 


20 


46 


21 


47 


22 


48 


23 


49 


24 


50 


25 


Total.. 


26 


428 i 65 I 493 











Table II. — Infestation in clover by Halticus citri, showing the number of eggs in leaf and 

where deposited. 



I/eaf No. 


Eggs 
deposited 
in upper 
surface. 


Eggs 
deposited 
in lower 
surface. 


Total 

number 

of eggs 

deposited. 


Leaf No. 


Eggs 
deposited 
in upper 
surface. 


Eggs 
deposited 
in lower 
surface. 


Total 

number 

of eggs 

deposited. 


1 

2 

3 


2 


n 


2 

4 

10 

12 
9 

16 
2 


10 

1 

4 

2 
3 
5 

10 
1 
2 
4 
1 
8 

1 
13 
12 


27 




1 1 

8 6 14 
5 1 6 

14 14 

9 3 12 

2 4 6 





28 


! 

n 

9 
14 


l 
3 
1 

2 


29 


4 


30... 




31 . 


6 


32 


7 


33 


8 


2 


31 


9 



10 

1 
4 








35 


1 


6 
1 
2 
1 
10 


1 

5 

2 


1 

3 3 

1 1 
i 6 
1 

4 6 

1 

1 11 
(i 
1 
5 

2 

1 s 


10 

11 

12 

13 

14 


33 


37 


38 




1 1 
3 (i 
5 
8 2 
1 

2 


33 


40 


15 


41 


16 


42 


17 


43 


18 


44 

45. 


19 


20 


4 

1 
6 

1 
10 

11 





2 


3 

1 


46. 


21 


47 


22 


48. 


4 1 4 
9 2 11 
3 3 


23 


49.. 


24 


50.. 


25 


Total... 


26 













GARDEN FLEA-HOPPER IN ALFALFA. 



11 



Table III. — Infestation in cowpeas by Ilalticus citri, showing the number of eggs in the 

leaf and where deposited. 





Eggs 


Eggs 


Total 




Eggs 


Eggs 


Total 




deposited 


deposited 


number 




deposited deposited 


number 




in upper 


in lower 


of eggs 




in upper 


in lower 


of eggs 




surface. 


surface. 


deposited. 




surface. 


surface. 


deposited. 


1 


4 


1 


5 


27 


9 





9 


2 











28 


3 


6 


9 


3 


1 





1 


29 


1 





1 


4 


2 





2 


30 


2 





2 













31 


(l 








6 


6 





C 


32 


6 





6 


7 


1 


6 


7 


33 


1 





1 


8 











34 


4 


1 


5 


9 


6 


2 


8 


35 


1 





1 


10 


9 





9 


36 


11 


2 


13 


11 


10 


2 


12 


37 





3 


3 


12 


4 
1 






4 
1 


38 

39 


o 
7 






2 

7 


13 


14 


2 






2 
5 


40 

41 


3 
2 


1 




4 
2 


15 


16 



8 
1 




1 
4 



9 
5 


42 

43 

44 


s 










1 



17 


18 


19 





8 


8 


45 


4 


1 


5 


20 


6 


1 


7 


46 


2 





2 


21 


4 





4 


47 


1 





1 


22 


6 





6 


48 


3 





3 


23 


1 





1 


49 


o 


1 


2 


21 


12 


2 


14 


50 


1 





1 


25 

26 


7 
2 



4 


7 
6 










Total... 


164 


46 


210 





In the field observations and laboratory studies it was found that 
Halticus citri prevails on a wide range of species of host plants. The 
following is a list of the host plants, as noted by the writer, together 
with those recorded in the literature: 

Alfalfa (Medicago saliva), red clover (Trifolium pratense), cowpeas ( Vigna sinensis), 
ragweed (Ambrosia artemisiaefolia) , hollyhock (Althaea rosea), ground cherry (Physalis 
pubescem), sorghum (Andropogon sorghum), prickly lettuce (Lactuca scariola), bur- 
dock (Arctium lappa), thistle (Cnicus arvensis), crab-grass (Syntherisma sanguinale), 
Kentucky bluegrass (Poa pratensis), oats (Avena satira), rye (Secale cereale), wheat 
(Tnticum vulgare), corn (Zea mays), rape (Brassica napiis), barley (Hordeam vvlgare), 
Jerusalem artichoke (Helianlhus tuberosus), Johnson grass (Andropogon halepensis), 
celery (Apium graveolens), wild mulberry ( Morus rubra), bur clover (Medicago 
arabica), sweet clover ( Mel Hot us alba), wild morning-glory (Convolvulus arvensis), 
hackberry (Celtis occidentalis) , cocklebur (Xanthium sp.), eggplant (Solamnu me- 
longe.no), Irish potato (Solanum tuberosum), sweet potato (Ipomoea batatas), peach 
(Amygdalus persica), cucumber (Cuctimis sp.), tomato (Lycopersicon lycoptrsicon), 
tobacco ( Nicotiana tabacum), bean (Phaseolus sp.), May-pops (Passifora incarnata), 
marigold ( Calendula officinalis), verbena ( Verbena incisa), cotton (Gossypium hirsutum), 
beggar-weed ( Mcibomia tortuosa,. white clover (Trifolium carolinianum). 

DESCRIPTION. 

ADULT. 

On first sight the brachvpterous female adult of this species 
(fig. 7) is likely to be confused with that of a flea-beetle, since both 
are saltatorial and resemble each other in 'color and general appear- 
ance, even though they represent two different orders. 



12 



BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 



The male (fig. 8) has the normal form of the Hemiptera, while 
the brachypterous female may easily be taken for another species. 
The macropterous female (fig. 9) rosembles the male, having long 
wings but is somewhat larger than the male. 

H. H. Knight, of the department of entomology, Cornell Uni- 
versity, Ithaca, N. Y., has kindly drafted the following redescription 
of the adult, from specimens furnished by the writer from Columbia, 
S. C. 

Slightly smaller and less shining than apterus L.; in addition to the vestiture of 
very fine pale pubescence, having on the dorsum deciduous tomentose patches which 
give silvery to greenish reflections as in intermedins Uhler. 

MALE (MACROPTEROUS). 

Length 2.1 mm. (1.9 to 2.1 mm.), width 0.74 
mm.; slightly smaller and more slender than 
the female. 

Head. — Length 0.22 mm., width across eyes 
0.56 mm., vertex 0.31 mm. Nearly vertical, 
front prominent, more or less sulcate at the 
base of the tylus; black, shining; carina form- 
ed by a sharp basal margin of the head. Rost- 
rum reaching to the posterior margin of the 
middle coxae; first two segment's black, the 
third and all but the apex of the fourth 
pale. 

Antennae. — Long and slender, reaching be- 
yond the tip of the membrane; segment I, 
length 0.25 mm., pale, sometimes darkened 
at the apex, two or three prominent bristles 
just before the tip; IT, 1.05 mm., black, linear, 
and slender; III, 0.83 mm., fuscous to black, 
usually pale at the base, more slender than the 
second; IV, 0.54 mm., fuscous, very slender. 
Pronotum. — Length 0.40 mm., width at base 0.74 mm., collar and calli not apparent; 
black, moderately shining, the disk having patches of deciduous tomentose pubescence 
as on the hemelytra. Scutellum, sternum, and pleurae black, moderately shining. 

Hem-elytra. — Sides nearly parallel; black, the clavus and corium having patches of 
deciduous tomentose pubescence, the patches arranged in more or less definite rows; 
cuneus black, the apex pale yellowish. Membrane pale, tinged with fuscous, one 
cell apparent but not distinct. 

Legs. — Long and slender, the hind femora saltatorial, coxa? black, front and middle 
femora pale yellow, the hind pair black with the apex pale; tibiae pale yellow, the 
hind pair fuscous near the base; tarsi pale yellowish, the tips fuscous, claws black. 

Venter. — Black, moderatelv shining, genital claspers small but distinctive of the 
species. 

FEMALE (MACROPTEROUS). 

Length 2.17 mm., width 0.95 mm., very similar to the male but more robust and 
having the second antennal segment and the femora differently colored. 

Head. — Length 0.25 mm., width across eyes 0.57 mm., vertex 0.31 mm.: not differ- 
ing from the male. 

Antenmr. — Segment I, length 0.22 mm., fuscous to blackish, paler at the base; 
II, 0.98 mm., pale with the basal and apical one-fourth blackish: III, 0.77 mm., 
fuscous, pale toward the base; IV, 0.48 mm., fuscous. 




Fig. 7. — Halticus citri: Brachypterous 
female. Greatly enlarged. 



GARDEN FLEA-HOPPER IN ALFALFA. 



13 



Pronotum. — Length 0.40 mm., width at base 0.85 mm., similar to the male. 

Hemelytra. — Width 0.97 mm., similar to the male. 

Legs. — Differing from the male in having the front and middle femora black with 
only the tips pale. 

Venter. — Black, moderately shining; ovipositor extending from a point near the 
tip of the hind cox;e. 

FEMALE (BRACHYPTEROLS). 

Length to tip of venter 1.6 mm., width 1.05 mm. Distinguished at once by its 
small ovate form and abbreviated hemelytra. Not differing from the macropterous 
female except in the form of the hemelytra and the absence of hind wings. 




Fig. 8. — Halticus citri: Male. Greatly enlarged. 



Fig. 9. — Halticus citri: Macropterous female. 
Greatly enlarged. 



Antennae. — Segment I, length 0.22 mm., pale fuscous, paler at the base; II, 0.97 
mm., pale, blackish at the base and apex; III, 0.85 mm., pale, fuscous toward the 
apex; IV, 0.57 mm., fuscous. 

Hemelytra. — Length 0.94 mm., not reaching to the tip of the venter; width 1.03 
mm.; rounded and convex, the membrane and the hind wings absent. 

The comparative lengths of adults of both sexes are shown in the 
following table: 

Table IV. — Comparative length of male and of brachypterous and macropterous female 
adults of the garden flea-hopper (Halticus citri). 





Specimen No. 




Length of 




Specimen No. 




Length (jf 






Male. 


Brachyp- 
terous 
female. 


Macrop- 
terous 
female. 


Male. 


Brachyp- 
terous 
female. 


Macrop- 
terous 
female. 


1 


Mm.. 
2.2 
2.0 
2.2 
2.2 
2.0 


Mm. 
1.7 
1.5 
1.6 
1.5 
1.7 


Mm. 
2.15 
2.17 
2.19 
2.15 
2.19 


6 


Mm. 
2.0 


Mm. 
1.6 


.1/ hi . 
2.17 






Average length. 

Average length of 8 

adults 






2.1 


1.6 




3 


2.17 


4 






1.95+ 













14 



BULLETIN 1)64, U. S. DEPARTMENT OF AGRICULTURE. 



EGG. 

Fig. 10. 

Egg cylindrical, roundly pointed at caudal end, broadly truncate at cephalic 
end. One side decidedly convex, opposite side slightly concave. Chorion smooth, 
lustrous, pearly white, semi transparent, free from sculpture, except surface of trun- 
cate end, which is roughly shagreened. Truncate end apparently with a collar, 
below which the egg is slightly constricted, end ellipsoidal in outline. Dimensions, 
long diameter, 0.21 mm., short diameter, 0.10 mm. Length of egg, outer angle 0.71 
mm., length of inner angle, 0.56 mm. Diameter at widest point, 0.20 mm. 

NYMPH. 

Figs. 11-15. 

The nymph resembles the adult in general outline and structure 
but differs in color, and has, in the place of wings such as the adults 





Fig. 10. — Halticua citri: o, Eggs in alfalfa leaf: 6; egg greatly 
enlarged. 



Fig. 11.— Haltkus citri: First 
nymphal instar. Greatly 
enlarged. 



have, dark-colored wing pads, these being most pronounced in the 
fifth stage. In the first nymphal instar the body is less robust and 
of a pale clay-yellow color at hatching which turns to pale green 
after feeding. During the period from the second to the fifth 
instars, inclusive, the thorax and abdomen increase in size laterally. 
The body gradually becomes more robust, and at the fifth instar it 
has assumed almost the shape and form of the adult. The color of 
the body varies from a light to a dark green. 

The period of time consumed in the development of the nymph 
ranges from 10 to 18 days, or an average of 14 days, as shown in 
Table V. 

FIRST INSTAR. 
Fig. 11 

Length 0.70 mm., width 0.19 mm. (average of 6 specimens). Number of body joints 
13. Segments of abdomen 10. Head, thorax, abdomen, and all appendages pale clay 
color. Head as wide as body, as long as wide. Eyes lateral and prominent, oval 
shaped, with hexagonal facet structure, carmine in color. Beak 0.21 mm. long; three 
joints, dark at apex. Antennae tubular; composed of four joints, first slightly swollen, 
length 0.08 mm., second 0.15 mm., third 0.20 mm., fourth 0.25 mm.; total length 0.68 
mm. 





T 


obex, 1916, at Columbia, S. C. 


- 














Total length of nymphal 
period. 


Mean 


Date of egg 
deposit. 


Date of 1 


th molt. 


Length 
stage V 


of j 






average 
tempera- 
ture. 




















Sex. 


Period 








Days, hours. 




Days, hours. 


"F. 


June 18 


June 20, $ 
do.. 


.m 

a. m 

p. m 

a. m 

a. m 


5 
4 

1 
4 
3 




5 




Male 

Female 

....do 

Male 

Female 


11 
17 
15 
17 
14 


19 
19 




i) 


76.6 


Do 


78. 7 


Do 


....do.. 


77.4 


Do 


June 20, \ 
do.. 


78.1 


Do 


77.4 


Do 


do.. 


p. in. . . . 


3 
3 

3 







Male 

Female 

Male 


11 
14 
14 




5 


77.4 


Do 


do.. 


77.4 


Do 


.....do.. 


77.4 


Do 


....do.. 


a. in — 
a. in 


2 
3 


19 



Female 

....do 


15 
14 







77.8 


Do 


do.. 


77.4 


Do 


do.. 


u. in 

a. m 


3 

3 


19 



Male 

Female 


15 
14 






77.8 


Do 


do.. 


77.4 


Do 


do.. 


). m 

a. m. . . . 


4 
4 
3 
4 


19 
19 




Male 

do 

Female 

do 


14 
14 
12 
16 




5 



77.4 


Do 


do... 


77.4 


Do 




77 


Do 


do. .. 


78.1 


Do 




[m 

a. ni 


4 
5 






Male 

do 


13 

15 






77.2 


Do 


do.. J 


77.8 


Do 


do... 


a. m 


4 





do 


14 





77.4 


Do 


do.. 


a. m 


4 





do 


16 





78.1 


Do 


do... 


1. in 


4 





do 


13 


It 


77.2 


Do 


do... 


a. in 


5 





do 


18 





77.8 




3.0 





14.1 





77.66 


July 24 


July 30, 9 
Aug. 7, 9 


la. in — 
} a. m 


3 
3 






Female 

do 


10 
10 



19 


79 


July 30 


80 


Do... 


. :. .do. - - 


) a. in — 
i p. in — 


3 
2 

2 



19 
5 


do 

Male 

Female 


11 
10 

10 




5 


80 


Do... 


....do... 


80 


Do 


do. . . 


80 


Do 


do... 


i a. m 





19 


Male 


11 





80 


Do 


do... 


i p. in — 


2 





do 


11) 


5 


80 


Do 


do. .. 


| a. in 

1 U. HI 

) a. in 

Da. m... 

! p. m 

j a. in 


2 


19 


do 


11 





80 


Do 


....do... 


2 
4 
3 
3 
2 

4 
3 


19 
5 
1 
5 



19 


Female 

Male 

do 

do 

do 

do 

do 


10 

11 

13 
10 
10 
12 
11 




5 
1 
5 







80 


Do 


do... 


so 


July 31 


Aug. 8, 9 
Aug. 9, 9 
do... 


80 




80 


Do 


80 


Do 


do... 


80 


Do 


do... 


i a. in 

>a. m 


SO 


Aug. 2 


Aug. 10, £ 
do... 


3 
3 
3 


17 




Male 

Female 


13 
13 
11 




5 


80 


Do 


80 


Aug.3 


Aug. 11, 92 p. m 


80 


Aug. 4 


do. . .10 a. in. . . 


2 


1 


do 


12 


1 


80 


Do 


do... 


t p. in — 

') a. in 

p.m.... 

3* a. Hi 


3 
3 
3 
4 
3 





19 



do 

Male 

do 

Female 


11 
11 
11 
11 
12 


5 


19 



80 




Aug. 10, i 
do... 


80 


Do 


80 


Aug. 6 


Aug. 17, : 
Aug. 19, I 


80 


Do 


80 











12 





79.95 


Oct. 2 


Oct. 11,9 
do... 


a. in 

a. in 


5 

4 






Male 

Female 


10 
14 







1 5 


Oct. 3 


l\ 


Oct.2 


do... 


a. m 


5 
5 






Male 

do 


16 
16 






71 




....do... 


71 


Oct 2 


do 


i 





Oct.. 3 


do... 


a. m 


5 





Female 


17 





71 






4.8 





15.8 

i 


1 


71 


















48309°— 


Bull 


964—21. (To 


face page 14.; 





Table V.— Number ofinstars, their length, and length ofnymphal life of Ealticus ritri during the months of June, July, August, and oXber, 19U, at Columbia, S. C. 



Date of egg 
deposit. 



June 18. 
Do.. 
Do.. 
Do. 
Do.. 
Do.. 
Do.. 
Do.. 
Do.. 
Do.. 
Do.. 
Do.. 
Do 

Liu.. 
Do.. 
Do 
Do., 

Do.. 
Do.. 
Do.. 
Do. . 
Do.. 



ulySO... 
Do 

Do 

Do 

Do 

Do 

Do 

Do 

Do 

July 31 

Aug. 1 

Do 

Do... 

Do 

lUg ■ 

Do 

Aug. 3 

Ail];. I 

Do.. .. 
lug 5 . 

Do.... 
Aug. 6.. .. 

Do.... 



Date of hatching 
of egg. 



June 26, 2 p. m. .. 

do 

do 

June 26, 9a.m... 

do. 

do. 



Date of first molt. 



June 28, 2 p. m. 
July 1, 2 p. m. . 
June 28, 2 p. m. 
do. 



June 29, 2 p. m. 
do 



June 28, 2 p. m. 

do 

do 

do 

do 

June 28, 9 a. m. 

do 

June 29, 9 a. m. 
June 28, 9 a. m. 
June 29, 9 a. m. 



Length of 
stage I. 



Days, hours. 



July 21 July 30, 9 a.m... 



\ lO.r.T 



Aug. 7, i) a. in 

..-..do 

....do 

....do 

. do 

....do 

....do 

....do 

....do 

Vug .\ 9 a. in 

Aug. 9, 9 a. m 

do 

....do 

....do 

Aug, Id, 9 u. in 

do 

Aug. 11, 9 a. in 

do 

....do 

Aug. 16, 9 a. in 

. do 

Aoj;. 17, J p. m 

Aug. 19, 9 a. in 



Aug. 1, 9 a. m.. 

Aug. 10, 9 a. m. 

do 

do 

do 

do 

Aug. 9,9 a.m.. 

Aug. 10, 9 a. in. 

Aug. 9, 9 a.m.. 
do 

Aug. in, 9 a. in. 

Aug. 11, 9 a. m. 

do 

do 

do 

Aug. 13, 9 a. m. 

do 

do 

do 

do 

Aug. 17, 9 a. m. 
Vug. 17, 2 p. in. 

Aug. 20,9 a. ii'- 

Aug. 21, 2 p. m. 



Date of second molt 




June 29, 2p.m.. 
July 4, 9 a. m. . 
July 1, 2 p. m. . 
July 1,9a. in.. 
July 2, 9 a.m.. 
July 3, 9 a. in. . 
July 2, 9 a. m.. 

do 

July 2, 2 a. m. . 
July 3, 9 a.m.. 
July 1,2 p.m.. 
July 2, 9 a. m. . 
June 30, 2 p. m. 

do 

July 2, 2 p. in. . 
Juiie 30, 2 )). m. 
July 1, 2 p. in.. 
June 30, 2 p. in. 

do 

July I, 2 ]>. in. . 
June 30, 2 p. m. 
July 1, 2 p. in. . 



Aug. 3, 
Aug. 11 
Aug. 12 
Aug. 11 
Aug. 11 

do. 

do. 

do. 

do. 

Aug. 10 
Aug. 13 
Aug. 12 

AllJi. 13 
Aug. 13 
Aug, 13 
Aug. 15 

do. 

do. 

do. 

do. 

Aug. 19 
Aug. 20 
Aug. 23 ; 

do. 



9 a. in.. 

, 2 p. in. 
, 9 a. in. 
, 2 p. in. 
, 9 a. m. 



9 a. in. 
9 a. m. 
2 p. m. 
9a. m. 
2 p. m. 
9 a. m. 
2 p. in. 



4 p. in. 
9 a. in . 
2 p. in. 



Oct. 16, 9 a. m.. 

. do 

Oct. 17, 2 p. in. 
Oct. 17.9a. in.. 



Oct. 16, 'i a. in.- 



Length of 
stage II. 



Date of third molt. 



June 30, 2 p. in. 
July 8,9 a.m.. 
July 3, 9 a. m. . 
July 4, 9 a.m.. 

do 

July 5, 9 a. m.. 

do 

July 5, 2 p. m . . 

do 

July 4,2 p.m.. 

do 

July 5,9a.m.. 
July 2, 2 p. m. . 

do 

July 3, 2 p. m. . 
July 2,9 a.m.. 
July 2, 2 p.m.. 
July 3, 2p.m... 
July 2, 2 p. in. , 
July 4, 2 p. m. . 
July 2,9 a.m.. 
Jidy 5, 9 a. in. . 



Aug. 5, 9 a. m. . 
Aug. 13, 2 p. in 

do 

do 

Aug. 13, 9 a. m. 

do 

do 

do 

Aug. 12, 2 p. m 
Aug. 12, 9 a. in 
Aug. 10, 9 a. in. 
Aug. It, 9 a. in. 
Aug. 15, 2 p. in 

do 

Aug. 1 1, I p. in 
4.Ug. 18, 2 p. Ill 
Aug. 17, 9 a. in. 

do 

Aug. 18,9 a. in. 
Aug. 17, 9 a. m. 
Aug. 23, 9 a. m. 
Aug. 23, 2 p. in. 
Aug. 24, 2 p. m. 
Aug. 25, 2 p. m. 



Oct. 19, 9 a. m. 

,9 a. in 

Oct. 19, 9 a. 111. 

....do 

Oct, 22,9a. in. 
Oct. 19, 9 a. ra. 



Length of 
stage III. 



Days, hours. 
1 



Date of fourth molt 





Aug. 7. 9 a. in 

Air.',. 15, 9 a. m ! 

do 

Aug. 14, 2p m 

Aug. 15, 9 a. in 

Aug. 15, 2 p, in ... 

do 

do 

Aug. 1 1, 2 p. in 

Aug. 11, 9 a. in 

Aug. 18, 9 a. m 

Aug. 10, >t a. in 

Aug. 17, 9 a. in 

do 

Aug. Hi, 2 p. in 

Aug, L9, 1 p. in 

I, 9 a. m 

Lug 19 ! p. m 

Aug. 21, 9 a. in 

Aug. 19, 2 p. m.... 
Aug. 2.',. 9 

, J p. m — 

Aug. 26, 2 p. in 

Aug. 28,9 a. ill 



9 a. in 

(in 21,9a. m 

Oct. 22,9 a. in 

do 

Moll slid 

iiri. 23, 9 a. m 



nil 91.4—21. (To face pago 14.) 



GARDEN" FLEA-HOPPER IN ALFALFA. 15 

Body: Widest at the head and thorax, caudal end bluntly pointed when viewed 
from the dorsum. 

Legs: Femur covered with long sparse hairs; tibia covered with numerous short, 
stiff, appressed hairs; tarsi covered with numerous short, stiff hairs, end of tarsi having 
two small hooks. 

SECOND INSTAR. 
Fig. 12. 

Length 0.81 mm., width 0.27 mm. at widest part of the body . Thorax and abdomen 
pale green, appendages clay color. Eyes lateral and prominent, oval shaped, with 
hexagonal facet structure, color carmine. Beak 0.32 mm.; of three joints, dark at 
apex, sucking tube brownish. Antennae tubular, of four joints, the first slightly 
swollen: amber colored, pubescent, hairs somewhat appressed; first joint 0.08 mm. in 
length, second 0.22 mm., third 0.25 mm., fourth 0.24 mm., total 0.79 mm. 

Body: Each segment with sparse, short, stiff hairs. Body widest at fifth abdominal 
segment, tapering bluntly at posterior extremity. 

Legs: Amber colored, femur covered with long, sparse hairs; tibia bearing short, 
stiff, appressed hairs; tarsi bearing numerous short, stiff hairs, end of tarsi having two 
small hooks. 




Fig. 12. — Halticus citri: Second nymphal Fig. 13. — Haltuus citri: Third nyinphal instar. 

iiistar. Greatly enlarged. Greatly enlarged. 

THIRD IXSTAR. 
Fig. 13. 

Length 1.03 mm., greatest body width 0.32 mm., width of head at widest point 
29 mm. 

Head brownish, thorax and abdomen varying in color from pale to dark green, 
appendages amber colored. Eyes lateral and prominent, oval shaped, with hexagonal 
facet structure, color carmine. Beak 0.38 mm. long, three-jointed, amber colored, 
terminal joints dark at apex. Sucking tube brownish. Antennae tubular, four- 
jointed, amber colored, pubescent, hairs somewhat appressed; first joint 0.29 mm. in 
length, second 0.31 mm., third 0.22 mm., fourth 0.13 mm., total length 0.95 mm. 

Body: Number of joints as in preceding instar. On dorsum of each joint one short, 
stiff hair and on lateral side of dorsum one stiff hair. Color pale green. Body widest 
at fifth abdominal segment, tapering bluntly at posterior extremity. 

Legs: Femur covered with long, sparse hairs; tibia bearing short, stiff, appressed 
hairs, tarsus bearing numerous short, stiff hairs, end of tarsi having two small hooks. 



16 



BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 



FOURTH IN8TAR. 
Fig. 14. 

Length 1.21 mm., width of body at widest point 0.44 mm., width of head at widest 
point 0.32 mm. Thorax and abdomen light to dark green, head brownish. Eyes lat- 
eral and prominent, oval shaped, with hexagonal facet structure, color carmine. Beak 
0.56 mm. long, of three joints, terminal joints dark at apex, sucking tube dark brown. 
Antenna? tubular, of four joints, the first slightly swollen; amber colored, pubescent, 
hairs somewhat appressed; first joint 0.15 mm. in length, second 0.38 mm., third 0.42 
mm., fourth 0.40 mm., total 1.35 mm. 

Body: Number of joints as in preceding instar. On dorsum of each joint are short, 
sparse, stiff hairs and on the side one short, stiff hair. Body light to dark green, wider 
than head at widest point, and tapering bluntly at posterior end. 

Legs: Straw colored, femur covered with long, sparse hairs; tibia coA'ered with 
numerous short, stiff, appressed hairs; tarsus bearing numerous short, stiff hairs. 




Fig. 14. — Halticus citri: Fourth nymphal instar. 
Greatly enlarged. 



Fig, 



15. — Halticus citri: Fifth nymphal instar. 
Greatly enlarged. 



FIFTH INSTAR. 
Fig. 15. 

Length 2 mm., width 0.98 mm. at widest point two-thirds of the way back from 
anterior end, height or depth of head 0.40 mm., widest point of head over the eyes 
0.51 mm. Color of head brownish, of thorax and abdomen pale to dark green. Eyes 
lateral and prominent, oval shaped, with hexagonal facet structure, color carmine. 
Beak 0.95 mm. long, of three joints, terminal joints dark at apex, sucking tube dark 
brown. Antenna? tubular, of four joints, amber colored, pubescent, more densely at 
apex, hairs somewhat appressed; first joint 0.19 mm. in length, slightly swollen; 
second 0.64 mm., tubular, slightly enlarged, and brown; third 0.64 mm., tubular, 
slender, pale; fourth 0.56 mm., tubular, slender, tapering acutely; total length 2.03 mm. 

Body: Abdomen with each joint bearing a short, stiff hair. Body dark green with 
dark wing pads, wider than head at widest point and tapering bluntly at posterior end. 

Legs: Femur bearing long, stiff hairs; tibia bearing numerous short, stiff, appressed 
hairs; tarsus bearing numerous short, stiff hairs. 



GARDEN FLEA-HOPPER IN ALFALFA. 17 

LIFE HISTORY AND HABITS. 

Difficulty was experienced in securing life-history records during 
the months of June, July, and August, because of excessive heat. 
Much patience was needed to bring the adults through the months 
of January and February, the natural hibernating period. To have 
the specimens under close observation it was necessary to confine 
them under more or less artificial conditions. The death rate under 
these conditions was very high. The combined lengths of the egg, 
nymph al, and adult stages under conditions at Columbia, S. C, 
varied with the temperature, being from 58 to 94 days, with an 
average of 76 days for all conditions. 

MATING. 

Mating usually takes place soon after the individual reaches matu- 
rity. In the series of experiments conducted by the author it took 
place from 5 minutes to 2 hours and 30 minutes after the last instar 
matured, usually occurring in the daytime. The time covered in 
the process of mating as recorded in a series of six experiments ranged 
from 30 minutes to 1 hour and 35 minutes. After mating, the indi- 
viduals in each case were observed to move in opposite directions 
and seek suitable places for feeding. 

The brachypterous females are much more abundant throughout 
the year and were used in nearty all of the life-history experiments. 
The macropterous female, however, which is very rare, was found 
to be fertile and to deposit fertile eggs as does the brachypterous 
form. 

OVIPOSITION. 

During the spring, summer, and fall, oviposition begins about 4 
days after mating according to Tables VI and VII, and was observed 
to take place principally during the night or earlv morning (see 
Table VII). 

Individuals of Halticus citri almost invariably oviposit on those 
portions of the plant where previously they have been feeding, the 
leaves usually being selected with a preference for the upper side 
(see Tables I, II, and III). In some instances, however, during the 
late fall and winter in cage experiments (see fig. 16) it was observed 
that oviposition took place in the. stem of the plant and also in the 
cork which constitutes the bottom of the cages. 



18 



BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 



Table VI. — Incubation records of eggs obtained from one female of the garden flea-hopper, 

Columbia, S. C, 1915 
Cage 15-631. 



Deposited— 


Hatched— 


Incu- 
bation 
period. 


Deposited — 


Hatched — 


Incu- 
bation 
period. 


Date. 


Num- 
ber of 
eggs. 


Date. 


Num- 
ber of 
eggs. 


Date. 


Num- 
ber of 
eggs. 


Date. 


Num- 
ber of 
eggs. 


July 28... 

29... 

30... 

31... 

Aug. 1 . . . 

2... 

3... 

4... 

5... 

6... 

7... 

8... 

9... 
10... 
11... 
12... 
13... 
14... 
15... 
16... 


4 
2 

2 

6 
4 
7 
2 
4 
2 
1 



4 








Aug. 5 
...do 
...do 
Aug. 8 
Aug. 11 
...do 
Aug. 9 
Aug. 14 
Aug. 11 
Aug. 14 


All. 
All. 
All. 
All. 
All. 
All. 
An. 
All. 
All. 
All. 


Days. 

8 

7 

6 

8 
10 

9 

6+ 
10- 

6+ 

8 


Aug. 17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

29 

30 

31 
Sept. 1 

Total 
Ave rage 
incubation 








3 

1 



>1? 







'0c? 






Days. 






















Sept. 2 


All. 


10 


Sept. 2 


All. 


7 














Sept. 5 


All. 


8 








Aug. 19 


All. 


9 




































43 
















8 





















i Dead. 
General average of 1.34 per day for 32-day period. 



Table VII. — Daily and total production of eggs deposited by one female of H. citri, time 
of hatching, and length of incubation period, Columbia, S. C, 1916. 

Cage 1. 5-1080. 



Deposited— 


Hatched— 


Incuba- 
tion 
period. 


Date. 


Number of eggs. 


Date. 


Number 
of eggs. 


Day. Night. 


Total. 


Sept. 4. 


1 




1 

1 
6 
3 
1 
5 
4 
9 
3 

12 
4 
8 
5 

10 
1 
2 
5 
1 
4 
1 
1 

6 
6 
2 
3 
3 

2 
2 
2 
2 
2 

1 
2 


Sept. 14 


All. 
All. 
All. 
All. 
All. 
All. 
All. 
All. 
All. 
All. 


Days. 
10 


5 


1 


Sept. 15 


10 


6 




6 
3 

1 
2 
4 


do 


8 


7 




Sept. 14 


8 


8 




Sept. 16 


8 


9. 


3 


Sept. 18 


9 


10. 


do 


8 


11 


7 


2 
3 
3 


Sept. 20 


9 


12. 


do 


9 


13. . 


9 
4 
6 


Sept. 22 


9 


14 






15 


2 


Sept. 24 


All. 
All. 
All. 
All. 
All. 
All. 
All. 
All. 
All. 
All. 


All. 
All. 


All. 
All. 


9 


16 


4 1 
4 


Sept. 25 


9 


17 


Sept. 26 


9 


18 




1 

2 
2 
1 
4 
1 
1 



Sept. 27 


9 


19 




Sept. 28... 


9 


20 


3 


Sept. 29 


9 


21 


do 


8 


22 




Sept. 30 


9 


23 




Oct. 1 


7 


24 




Oct. 2... 


7 


25 







n 


26 


3 3 
3 


Oct. 5... 


10 


27 


Oct. 6 


10 


28 




2 
3 


Oct. 13. 




29 




Oct. 9 . 


10 


30 




3 


2 


Oct. 10... 


10 


Oct. 1 









2 


Oct. 10... 


All. 
All. 
All. 

All. 
All. 


9 


3 


2 


Oct. 11... 


9 


4 


2 


Oct. 12... 


8 


5 


2 
2 



Oct. 14. 


8 


6 




...do.... 


8 


7 




1 

2 

Dead. 






8 


Oct. 15... 


All. 
All. 


8 


9 




Oct. 17... 


8 


Nov. 3 


8 
















Total 


53 


67 1 120 












8.04 















GARDEN FLEA-HOPPER IN ALFALFA. 19 

The female assumes the usual feeding position in which the body 
is parallel with the surface of the leaf. Apparently after a desirable 
place is located with the proboscis a puncture is made; the curved or 
swordlike ovipositor is then advanced to the puncture made by the pro- 
boscis immediately after the removal of the proboscis; the ovipositor 
penetrates the puncture to its full length, and an egg is deposited 
in the cavity. After the ovipositor is withdrawn a large drop of clear 
fluid exudes from it, covering the exposed truncate end of the egg. 

The process of oviposition requires about 15 to 20 seconds, only 
one egg being placed in each hole. 

EFFECT OF TEMPERATURE ON OVIPOSITION. 

It was found that oviposition ceased when the temperature fell 
below 70° F., and there were no records of oviposition at tempera- 
tures above 90° F. In a number of cages (fig. 16) each containing two 
male and one female flea-hoppers were placed in a well-ventilated 
basement room of the laboratory, the temperature of which ranged 
between 75° and 90° F., most of the eggs were deposited in the 
daytime when a temperature of about 80° F. was reached, which 
usually occurred in the early morning. 

EGG STAGE AND PROCESS OF HATCHING. 

Several days before hatching the egg changes from its original 
pearly white to a pale clay-yellow color, this change being evidence 
of its fertility. The color of the egg resembles that of the nymph at 
emergence. The shape and position of the nymph, including the 
segments of the abdomen, the thorax, the head, the appendages, and 
the carmine-colored eyes, are distinguishable under a lens. In the 
egg the nymph is found with its head at the truncate end a short 
time before hatching, the covering of this end being broken at the 
edge or through the middle, and opening, in most cases, like a trap- 
door. The head appears through the opening followed by the thorax 
and abdomen. The body moves backward and forward in an effort 
to disengage the appendages from the chorion. The appendages are 
all laid snugly against the ventral side of the body. The proboscis 
is the first appendage to be released, followed by the pro thoracic and 
mesothoracic legs. These are then utilized to free the antennas and 
metathoracic legs. The entire process requires about one hour. 

The egg is slightly swollen before hatching. Following the emer- 
gence of the nymph the eggshell collapses and is semitransparent 
with red pentagonal to polygonal markings. The body and legs of 
the freshly emerged nymph are pale clay-yellow color, the antennae 
straw color, and the eyes carmine. The egg period was found to 
range from a minimum of 6 days to a maximum of 16 days in the 
experiments carried out, with an average incubation period of 11 
days. 



20 



BULLETIN 964, TJ. S. DEPARTMENT OF AGRICULTURE. 



NUMBER AND LENGTH OF INSTARS. 

There are five instars. The length of the instars as well as the 
total length of the nymphal life is slightly variable, as may be noted 
by reference to Table V. What slight variations there were in the 
length of these instars may have been due, in large measure, to differ- 
ences of temperature and food supply. 

The intervals between each two instars gradually increases as 
maturity is reached. There was found to be no relation between 
the length of the periods and the sex of the individual. 

LENGTH OF LIFE OF THE ADULT. 

Adults of Halticus citri lived for from 9 to 94 days in the rearing 
experiments, as is shown in Table VIII. The sexual development 
was found to be complete as soon as they became adults. The 
females are shown to have lived longer than the males. 

Table VIII. — Length of life of adults of Halticus citri. 



No. 


Male. 


Female. 


Emerged. 


Died. 


Days. 


Emerged. 


Died. 


Days. 


1 

2 

3 

4 


July 10 
July 13 
July 10 
...do 


Aug. 9 
Aug. 26 
July 19 
...do 


30 
44 
9 
9 
13 
13 
23 
26 
94 


July 13 
...do 
July 15 
July 12 
Aug. 15 
Aug. 17 
Aug. 31 
Oct. 27 
Oct. 28 


Aug. 29 
Aug. 10 
Aug. 31 
Aug. 6 
Sept. 10 
Sept. 2 
Nov. 3 
Jan. 13 
Jan. 16 


42 
28 
47 
25 
26 
16 
64 
78 
70 

44 


5 

G 

7 

8 

9 


July 13 
Aug. 17 
Aug. 18 
Oct. 27 
...do.... 


July 26 
Aug. 30 
Sept. 10 
Dec. 22 
Jan. 29 




Ay. 













HIBERNATION. 



In experiments carried out by the writer, the last remaining indi- 
viduals of the adults which had emerged on October 27, 1915, died 
on Januar}^ 29, 1916. Other adults of both sexes issued December 
18, 1915, and hibernated until March 14, 1916, when they became 
active again. Eggs were found in the cage on this date. First- 
stage nymphs w^re discovered on April 2, 1916. 

The garden flea-hopper is found in greatest abundance during 
August and September, and gradually decreases in number as winter 
approaches. In the latitude of Columbia, S. C, mortality is greatest 
in December, very small numbers being found after this date. Many 
of the adults apparently are killed by the cold weather, and the 
remainder seek winter protection under the thickest bunches of their 
favorite host plants, along fences and other well-protected places, 
where they continue to winter until the plants become green again 
in the spring, and then deposit eggs before perishing. 



GARDEN FLEA-HOPPER IN ALFALFA. 21 

SPRING APPEARANCE AND NUMBER OF GENERATIONS. 

The adults of the garden flea-hopper in the latitude of Columbia, 
S. C, usually appear about the middle of March. Much depends 
upon the season, however, and they have been found soon after the 
host plants become green and spring is well in evidence. The adults 
appeared and deposited eggs as early as March 14, 1915, in the field 
experiments at Columbia, which was the earliest date recorded of 
the discovery of eggs in the outdoor experiments. Eggs have been 
secured in the outdoor cages throughout the year, beginning with 
the middle of March and continuing until the last of November. 
From five to six generations were reared at the Columbia laboratory. 
The length of life of each individual is determined largely by the 
length of life of the adult stage, this being the longest period of the life 
cycle. 

The first generation was found to extend from March 14, 1915, 
when fertile eggs were first deposited, to May 15, 1915; the second 
generation extended from May 15 to July 12, 1915; the third from 
July 12 to September 11; the fourth from September 11 to November 
18, and the fifth from November 18, 1915, to February 10, 1916. 

FEEDING HABITS. 

In almost every instance noted the youngest plants are attacked in 
preference to the older and more vigorous growths, and when the 
insects start feeding on a plant they apparently continue until all 
the sap is extracted, giving the plant a bleached appearance. During 
the warm seasons the tendency is to feed at the top of the plants, but 
during cool days and seasons the}^ feed rather at the bases of the 
plants. It has been noticed that during warm days the individuals 
seem to show no particular inclination for protection from the sun 
by seeking the shady side of the leaf. When they are disturbed, 
however, they immediately seek a place of concealment on the plant 
or hop to the ground in quest of protection. 

In feeding on the host plant, the individual places itself in a posi- 
tion parallel to the surface of the leaf, preferably on the upper surface, 
with its legs resting on the surface. Then the proboscis is swung 
down from the ventral side of the body to a perpendicular position 
and the apex is thrust into the epidermis of the leaf at a point mid- 
way between the prothoracic legs, the proboscis is hinged at the 
second articulation, the head and thorax being bent slightly down- 
ward to allow the first and third articulations to meet, the sucking 
tube remains straight as the open sheaths of the second and third 
segments leave the sucking tube, and a slight pressure is placed on 
the apex of the proboscis. A mechanical procedure ensues similar 
to the pumping process, in which the head and thorax move slightly 
upward and downward, not sufficiently, however, to straighten the 



22 



BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 



second and third joints of the proboscis. Probably in this pumping 
procedure the food is taken into the body through the proboscis. 
After continuing this process for several minutes at a time the pro- 
boscis is straightened and drawn from the tissue of the leaf and swung 
to its natural position on the ventral surface of the body for a short 
time ; then it is again swung down and cleansed by a stroking process 
with the forelegs which clasp the proboscis between the tarsal joints. 
After gradually sliding the proboscis through them the insect starts 
feeding again. 

This habit has been noted alike in all ages of the nymph and adults, 
both males and females. 




Fig. 16.— Type of cage used in conducting molting experiments with the garden flea-hopper. 
PROTECTIVE HABITS. 

Both the males and females arc saltatorial, as the metathoracic 
legs are much longer and stronger than the others. The male is 
found to be decidedly more active than the brachypterous female, a 
fact probably due to the possession, in addition, of true wings. The 
adult individuals generally are active and strong as runners and hop- 
pers. When they are only slightly disturbed they hasten imme- 
diately for concealment to the opposite side of the leaf of the plant. 
If the approaching object, however, appears with a violent disturb- 
ance, the individual will hop many times its own length to the ground 
or to another plant where immediate protection may be found. 









GARDEN FLEA-HOPPER IN ALFALFA. 



23 



In a number of experiments different individuals were placed on a 
large horizontal screen within the room, and the distance of jumps 
made on the screen ranged from three inches to nearly three feet. 
In the latter instances they seemingly sustained themselves in the 
air by the aid of their wings. 

The nymphs of the first stage are not saltatorial until nearly time 
for molting; when disturbed, then, they show slight saltatorial ten- 
dencies but are usually very quiet even when disturbed, and merely 
move slowly to another position on the plant out of danger. They 
feed on the same place sometimes through several instars. The last 
three or four instars of the nymph have the same habits of locomo- 
tion and are as active as the adults. 




Fig. 17.— Type of cage used in conducting rearing experiments with the garden flea-hopper. 
REARING METHODS. 

Some difficulty was experienced in acquiring a satisfactory and 
serviceable rearing cage for the different experiments carried on 
with this species. Test tubes (fig. 16) were first used as containers 
for molting experiments and lamp-chimney cages for life-history 
work. The inaccuracy of the results with these rearing cages neces- 
sitated the substitution of one which would be more convenient. 
The best results were obtained with rearing cages constructed of 1 
and 2-inch glass cylinders with cork bases and cloth tops sealed at 
the edges with glue (fig. 17), each cork base containing 9 by 36 mm. 
vials with water, and plant food for the insects. The 1-inch cages 
were attended with greatest success in molting experiments, while the 
2-inch cages were used with advantage in life-history work. 



24 BULLETIN 964, IT. S. DEPARTMENT OF AGRICULTURE. 

NATURAL ENEMIES. 

Repeated observations have shown that because of the alertness 
and saltatorial habits of the nearly grown nymphs and adults of the 
garden flea-hopper their chances of being attacked by natural enemies 
are somewhat meager. The nymph in the earlier stages, however, 
is known to be less active and is frequently attacked by the larva of a 
small red predacious mite of the family Erythraeidae. The writer 
also reared a number of egg parasites which have been determined 
by A. G. Gahan as representing the following species: 

Anaphes perdubius Girault. Tetrastichus sp. 

Gonatocerus sp. Anagrus armatus nigriventris Gir. 

Westwoodella americana Ashm. Abbella subflava <!ir. 

These species have been reared from the eggs of the garden flea- 
hopper collected from the alfalfa fields where the outbreaks occurred, 
and the parasites were believed to have rendered an appreciable 
amount of good. 

REMEDIAL AND PREVENTIVE MEASURES. 

Since the garden flea-hopper has an extremely wide range of food 
plants, though alfalfa is one of its favorite hosts, rotation as a remedy 
would be out of the question. Clean culture, however, to prevent 
hibernation in weeds and trash was found to result favorably in 
controlling the overwintering adults and is the most adequate means 
thus far devised of reducing the numbers of the pest. 

In alfalfa fields where outbreaks of the garden flea-hopper occurred 
it was observed that timing the removal of the crop so as to destroy 
the eggs was a vital factor in control. Although a small percentage 
of the eggs is laid near the ground, the larger proportion is deposited 
in the delicate leaves and petioles. Some of these leaves containing 
eggs drop to the ground, it is true, and in numerous cases these eggs 
hatch; nevertheless, timely cutting will remove the larger number, 
and this measure is recommended in controlling an outbreak. 

DUSTING AND SPRAYING TESTS IN THE FIELD. 

A dusting experiment was conducted in one of the alfalfa fields 
where an outbreak of the garden flea-hopper occurred, the damaged 
crop being cut and removed from the infested field. An area of 100 
square feet was selected and treated thoroughly with a mixture of 
air-slaked lime and flowers of sulphur in equal proportions. The 
mixture was thoroughly applied with a hand duster, one application 
being made in the morning and another at midday. Repeated 
observations by the writer after the dusting was completed failed to 
show that the treatment had been effective on any stages of the flea- 
hopper. 

In the same field a plat of similar size was treated with a spray 
solution composed of potassium sulphid and water at the rate of 1 



GARDEN FLEA-HOPPER IN ALFALFA. 25 

ounce of the potassium sulphid to 5 gallons of water, a hand sprayer 
of the compressed-air type being used. The plat was thoroughly 
sprayed in the morning and also at midday, but even when a stronger 
solution was employed there was little appreciable benefit from the 
application. 

A spray of kerosene emulsion was next tried on three experimental 
plats of alfalfa, each having an area of 100 square feet. The alfalfa 
had been cut and removed a few days before, and the moist weather 
was causing the new crop to grow rapidly. The stock emulsion was 
prepared by the following method : One-half pound of laundry -soap 
was dissolved in 1 gallon of hot water; the solution was then removed 
from the fire, and after 2 gallons of kerosene had been added the 
material was violently agitated. The table of strengths, as applied 
in their order on the three plats, follows: 

7 per cent strength, Si gallons of water added to 1 gallon of stock solution. 
10 per cent strength, 5f gallons of water added to 1 gallon of stock solution. 
12 per cent strength, 4% gallons of water added to 1 gallon of stock solution. 

Observations were continued for one day after the spraying experi- 
ments were started, and the following results were recorded: The 7 
per cent kerosene emulsion was very effective in destroying the 
garden flea-hopper in all stages; the 10 per cent solution killed 
practically all the flea-hoppers and did not materially affect the 
alfalfa; the 12 per cent solution destroyed all of the insects but 
damaged the alfalfa crop noticeably. 

In the campaign against the garden flea-hopper about 12 acres of 
fields where the most severe outbreaks occurred were sprayed with 
10 per cent kerosene emulsion with great success. The solution was 
applied with an orchard power sprayer having two nozzles, the spray 
being delivered from the machine at a gauge pressure of 80 pounds 
and covering a strip 18 feet wide. The machine was driven by a team 
of mules, and the nozzles were operated by two men at the rear of the 
machine. An average of 30 gallons was applied to each acre. The 
cost per gallon of the solution was about 4 cents, thus making the 
estimated cost per acre $1.20, nothing being added for labor and 
machinery, since the farmers had these at their immediate disposal. 
Since it was estimated that the yield of hay would be a ton per acre 
under normal conditions, and since spraying with kerosene emulsion 
as described costs approximately $1.20 per acre and effects an almost 
complete saving of the crop, the market price of which has been $20 
per ton, this treatment ma}^ be recommended as a satisfactory and 
economical measure of control. 

The only other method of control which effectively overcame the 
pest was the plowing under of the infested crop, which was done in 
a number of cases where many of the plants had been killed by the 



26 BULLETIN 964, U. S. DEPARTMENT OF AGRICULTURE. 

insect. There are objections to this measure, however, particularly 

in fields having a good stand. Much labor and expense are required 

to make a seed bed and to crop the land, and a measure which would 

involve repetition of these operations would tend to discourage the 

growing of alfalfa. 

SUMMARY. 

One of the most striking hemipterous forms of the family Capsidae 
is the garden flea-hopper, Halticus citri Ashm. The male adult has 
the typical capsid form with long wings, while the female adult 
differs in appearance, being wingless with a convex robust figure 
suggesting to the observer a new species. Rarely, female adults are 
found which resemble the males in general appearance, except that 
they are more robust and have long wings ; this form, however, upon 
close observation is found to be a trifle larger with a more robust body 
together with a more perfectly shaped head and thorax, and its 
genitalia resemble those of the wingless female. 

The individuals hop and jump about in the meadow in the manner 
of leafhoppers. The males are more active than the females, prob- 
ably because they have functional wings. 

In South Carolina and Georgia these insects become abundant in 
early summer and continue so until late fall, when they gradually 
disappear, the older individuals dying and the younger seeking hiber- 
nation quarters under or at the base of their favorite host plants and 
in protected places such as fences, terraces, or shrubbery. 

Both nymphs and adults suck sap from punctures made in the 
leaves, petioles, and stems of the plants, causing discoloration, wilting, 
and, in severe infestation, death. 

Leguminous plants appear to constitute its favorite foods and 
places for breeding, although its range of host plants is extremely 
wide. 

The eggs are deposited in the leaves and petioles of the food plants, 
usually in places where adults have been feeding. 

The incubation period of the egg at Columbia, S. C, covered from 
6 to 16 days with an average of 11 days. The five instars of the 
nymph stage together cover from 10 to 18 days with an average 
of 14 days. The combined length of nymph and adult stages was 
25 days. 

In the latitude of South Carolina there are from five to six genera- 
tions annually. The species was found to hibernate in the adult stage. 

The garden flea-hopper is little affected by natural enemies, but 
changes in weather reduce its numbers during the winter months. 

Hibernation and subsequent multiplication are prevented where 
weeds and plants that remain green late in the fall and resume growth 
in the spring are cleaned up in the fall and destroyed. 



GAKDEN FLEA-HOPPER IN ALFALFA. 27 

In the case of severe outbreaks of the garden flea-hopper it is ad- 
visable to cut and remove the invaded crop and then spray the field 
with a 10 per cent solution of kerosene emulsion. 

LITERATURE CITED. 

(1) ASHMEAD, W. H. 

1887. Hemipterological contribution' (No. 1). In Ent. Americana, v. 3, 
no. 8, p. 155-166. 

(2) Popenoe, E. A., Mason, S. C, Marlatt, F. A. 

1890. Some insects injurious to the bean. In Kansas Sta. Agr. Exp. Sta., 
Second Ann. Rept., 1889, p. 206-212. 

(3) Giard, A. 

1892. Sur mi h6miptere-het£roptere (Halticus minutus Reuter) qui ravage 

les arachides en Gochinchine. In Compt. Rend. Soc. Biol. Paris, 
v. 4, n. s., p. 79-82. 

(4) Distant, W. L. 

1893. Biologia Oentrali-Americana. Insecta. Rhynchota. Hemiptera-Hete- 

roptera. v. 1. 

(5) Uhler, P. R. 

L893. Summary of the collection of Hemiptera secured by Mr. E. A. S< hwarz 
in Utah. In Proc. Ent, Soc. Wash., v. 2, no. 4, p. 366-384. 
(lb Smith, J. B. 

1900. Insects of New Jersey. Supplement to the 27th Ann. Rept. State 
Board of Agr., 1S99. 755 p., 328 fig., map. 

(7) Webster, F. M. 

1900. Some insect notes. In Ent. News, v. 11, no. 4, p. 436-439. 

(8) Chittenden, F. H. 

1902. The garden flea-hopper (Halticus uhleri Giard). U. S. Dept. Agr. 
Div. Ent. Bui. 33 (n. s.). 

(9) Britton, W. E. 

1905. Fourth report of the State entomologist of Connecticut. In Rept. Conn. 
Agr. Exp. Sta. 1904. 

(10) Chittenden, F. H. 

1907. Insects injurious to vegetables. New York. 262 p., 163 figs. 

(11) Bureau of Entomology. 

1909. Principal injurious insects of the year 1908. In U. S. Dept. Agr. Year- 
book for 1908, p. 567-580. 

(12) Reuter, 0. M. 

1909. Bemerkungen fiber nearktische Capsiden nebst Beschreibung neuer 
Arten. In Acta Soc. Sci. Fennicae, v. 36, no. 2. 

(13) Davis, J. J. 

1912. Report on insects injurious to flowering and ornamental greenhouse 
plants in Illinois. In 27th Rept. State Ent. 111., p. 83-143. 

(14) Sanborn, C. E. 

1912. Garden and truck crop insect pests. Oklahoma Agr. Exp. Sta. Bui. 100. 

(15) Barber, H. G. 

1914. Insects of Florida. II. Hemiptera. In Bui. Amer. Mus. Nat, Hist., 
v. 33, p. 495-53:.. 



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